shouldStartLoadWithRequest doesn't run stringByEvaluatingJavaScriptFromString method - iphone

Question

I am trying to run the code below in webview's shouldStartLoadWithRequest delegate method but it doesn't make any changes.
- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType{
NSLog(#"webView shouldStartLoadingWithRequest");
[self.webView stringByEvaluatingJavaScriptFromString:[NSString stringWithFormat:#"document.execCommand('bold', false,null)"]];
return TRUE;
}
There is no error, it prints the NSLog and everything in the method works great except "stringByEvaluatingJavaScriptFromString" method.
But if I try to make text bold in another function, for example an IBAction method, works fine.
-(IBAction)boldClick:(id)sender
{
[self.webView stringByEvaluatingJavaScriptFromString:[NSString stringWithFormat:#"document.execCommand('bold', false,null)"]];
}
Actually, this is my company's special application and this UIWebView will not show the web pages. I am using it to show some custom HTML pages.
I need to make everything in "shouldStartLoadWithRequest" because I am trying to run an objective-c method from javascript.
UPDATE
- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType{
// Break apart request URL
NSString *requestString = [[request URL] absoluteString];
NSArray *components = [requestString componentsSeparatedByString:#":"];
// Check for your protocol
if ([components count]==3)
{
[self makeBoldText];
return NO;
}
else
{
return TRUE;
}
}
-(void)makeBoldText
{
[self.webView stringByEvaluatingJavaScriptFromString:[NSString stringWithFormat:#"document.execCommand('bold', false,null)"]];
}

Answer 1

The doc says that method webView:shouldStartLoadWithRequest: is sent before a web view begins loading a frame. After you return YES in this method, web view starts loading a request. So any javascript you execute will have no effect, because a new page will be loaded after your JS call.
You can probably use webViewDidFinishLoad: method to execute javascript after page finishes to load. Or if you want to trigger JS by clicking on a link, you can use shouldStartLoadWithRequest but return NO from it.